Safety-valve.



PATENTED OCT. 29. 1907.

L. SGHUTTE, DECD.

GUARANTEE TRUST & sun DEPOSIT 00., AND M. n. SOHUTTE. nxnouwons.

SAFETY VALVE.

APPLIOA'IION FILED JAN.1B,1906.

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UNITED PATENT OFFICE.

LO UIS SUIIUTTE, OF PHILADELPHIA, PENNSYIIVA N M; GUARANTEE TRUST & SAFEDEPOSIT CO. AND MARY D. SCIIUTTE, EXECU IORS Ol SAID LOUIS SOHUTTE,DECEASED, ASSIGN- ORS TO SOIIUTTE AND KOERTINO COMPANY, OF

CORPORATION OF PENNSYLVANIA.

PHILADELPHIA, PENNSYLVANIA, A

SAFETY-VALVE.

Specification of Letters Patent.

Patented Oct. 29, 1907.

Application filed \Tn nuarv 18' 1905- Serial No. 241,624.

To all 'u'hom it may concern:

Be it known that 1, Louis Scne'r'rs, a citizen of the United States ofAmerica, residing in the city and county of Philadelphia, in the Stateof Pennsylvania, have invented a certain new and useful improvement inSafety-Valves, of which the following is a true and exact description,reference being bad to the accompanying drawings, which form a partthereof.

My invention relates to the construction of safety valves and has forits object to provide a valve which shall be free from the usual markedtendency to chatter and which is mainly characterized by the use inconnection with the main safety valve of a pilot valve which determinesthe movements of the main safety valve.

My improvements will be best understood as described in connection withthe drawing in which they are illustrated, and in which i (1, indicatesthe entrance passage leading into the valve casing, and b, the exitpassage from the. valve casing, a, being the seat for the safety valveand the valve casing having opposite to the seat and on the admissionside of the casing a cylinder 0 the diameter of which is slightlygreater than the effective area of the valve seat at, that is to say,the diameter of the valve seat which is covered by the valve when St*ated.

O, isthe valve which is provided with a piston extension O, forming aloose fit in the cylinder 0 as indicated.

In my present construction I provide the valve casing with a by-passconnecting the admission and delivery sides of the casing, in whichby-pass is formed a small valve seat P, and below it a cylindricalchamber P, between which and the valve seat P, is preferal lyformed anenlarged chamber P The upper part of the cylindrical chamber P, isconnected with the cylinder 0 through a passage-O leading into thecylindrical chamber through a port P P, indi eating the port connectingthe cylindrical chamber with the admission side of the casing'and R, theport connecting the top of the cylindrical chamber above the valve seatwith the delivery side of the casing.

Q, is a valve adapted to seat itself on the seat P and having attachedto it, a disk Q which forms a loose fit with the cylinder I, below theport P By preference the valve has also attached to it a disk or pistonQ, fitting loosely in the top of the cylindrical chamber P, and soplaced that when the valve Q, rises from its seat, the disk Q, is liftedinto the enhrged chamber P The valve Q, which I call the pilot valve, isheld to its seat by any convenient yielding means, but preferably bymeans acting with decreasing force as the valve moves away from itsseat; thus, as shown, the spindle E, which presses the valve to its seatis acted on by a lever F pivoted to the spindle at F, and at F pivotedto a link F, the lever F, whenthe valve is seated keeping a horizontalposition and being acted on by a weight F. It will be obvious that asthe lever is moved upward by the valve in rising the valve F, Will takea slanting position, with the effect of decreasing, the leverage exertedby the weight F This feature of construction as also the generalconstruction of the pilot valve considered as a safety valve, forms thesubject matter of my co-pending application filed January 18, 1905,Serial Number 241,623.

S, is the spindle by which the safety valve 0 can be held to its seatwhen desired, the spindle S, being retracted by a screw stem S l Innormal operation, both the valves 0, and Q, being seated, the cylinder 0and the cylinder P, will be filled with steam or other fluid under thesame pressure as exists in the entrance chamber a, of the casing, andthe entire area of the valve 0, will be under this pressure. When thepressure however rises to the point at which the valve Q, is set toopen, that valve will be lifted from its seat and the fluid in thecylinder 0 will at once escape through the pilot safety valve, reducingthe pressure in cylinder 0 to that existing on the side b, of the casingwhereupon the pressure in the chamber a, acting on the slightly greaterarea of the piston O, will open the valve 0, and permit the directescape of fluid from the chamher a, to the chamber 1), the valveremaining open until the pressure in chamber a, has fallen to such apoint that the pilot will again seat itself when normal conditions arerestored when the pressure in the cylinder 0 reaches or nearly reachesthe pressure in the chamber a. The direct escape in any considerablevolume of the fluid from the chamber a, into the port R, is prevented bythe disk Q and the cylinder P, and by preference the additional disk orcylinder Q, is employed so that as soon as the valve Q, opens and thepressure fluid escapes from the chamber P the full pressure of the fluidin the cylinder O will be exerted on the disk or piston Q, to force itand the valve Q, upward until the disk has passed into the chamber P andthe fluid has a free escape through that chamber and the port It.

Having now described my'invention, what I claim cylinder 1, and meansacting to hold the pilot valve to its seat.

2. A safety valve having: in combination. a valve seat u, and a cylinder0 situated in front of said seal, a cylindrical chamber 1', at one sideof the valve seat a, said chamber having a valve seat 1", at its top, aport i, at its bottom connecting it Willi the admission side of thecasing, a port l", at its side, and laterally expanded chamber 1'",above port if, a conduit from the top of the cylinder i, to the deliveryside of the casing, a conduit. from port i"-, to the cylinder a valve(I. adapted to seat. itself on seat a, and having a piston 0, otIslightly greater diameter form ing a leaky lit in cylinder 0-, a valvet2, seated on seat 1", and having, a disk Q, forming a leaky iii. in thecylinder 1, between port l", and chamber 1', a second disk Q fitting acylinder 1, below port P and also attached to valve Q, and means actingwith regulated force to seat valve Q.

2;. A'safety valve having in combination a valve seat a", and a cylinder0 situated in front of said seat. a cylindrical chamber 1, at one sideof the valve seat I13, said chamber having. a valve seat 1, at its top,a port 1", at its bottom connecting it with the admission side of thecasing, a port l"-, at its side and a laterally expanded chamber 1'",above port 1' a conduit from the top of the cylinder i, to the deliveryside of the casing, a conduit from port P to the cylinder (5 a valve 0,adapted to seat itself on seat a", and having, a piston 0', of slightlygreater diameter forming a leaky fit in cylinder 0-, a valve Q, seatedon seat 1", and having a disk Q, forming a leaky tit in the cylinder 1',

between port P and chamber P, a second disk Q fitting in cylinder i,below port 1", and also attached to valve Q, and means acting to seal.valve Q, and ith decrasing force as said valve recedes from its seat.

4. in a. safety valve construction the combination with an inlet andexhaust. passage, of a main pressure valve adapted to establishcommunication between said passages, a. by-pass around said valve, thesaid main valve having a piston extension of larger pressure area thanthat of the main valve, a chamber in which said piston extensionoperates, a minute communication between said inlet passage. and saidchamber, a cylindrical chamber forming a part oil said by-pass, a meansof communication between said cylindrical chamber and the firsttnentioned chamber, a loaded supplemental valve adapted to operatepartly'within said cylindrical chamber, the said supplemental valvebeim, exposed to the pressure within said inlet passage and said firstmentioned chamber for the purpose of relicvin the pressure on the mainvalve within the inlet passage and i the lirst mentioned chamber.

5'. in a safety valve construction having an inlet passage and a pistonextension on the main valve operating in a chamber, the combination witha by-pass around said valve, of a cylindrical chamber forming a part ofsaid bypass, the said cylindrical chamber having an enlarged cir-

